We just released MonoTouch 4.0, a product to build iOS
applications using C# and .NET. We also released our new
Mono
for Android product.

New in MonoTouch 4.0

MonoTouch 4.0 is a major upgrade to our product as it
upgrades the Mono runtime engine from the old, trusted and
friendly Mono 2.6 to the latest and greatest Mono
2.10 core, these are some of the new features available as
part of this upgrade:

Parallel Frameworks for C#: Great APIs for
building multi-threaded software. Not only this is
great for iPad 2 users and developers, but it also
simplifies just plain multi-threaded programming by
exposing Futures, Tasks and Parallel LINQ to the
developer.

LLVM Compiler Support: In addition to the fast
Mono compilation engine, MonoTouch can now also use
LLVM to create optimized builds. When you build
MonoTouch applications using LLVM your executables
will run faster, they will be smaller, and you can
optionally opt into generating the nimbler ARMv7 or
Thumb code (fat binaries are also supported).

C# 4.0 and .NET 4.0: This release comes with the
latest incarnation of the C# language as well as
exposing the new .NET 4.0 APIs (many new functional
constructs make for nicer looking code, like all the
IEnumerable enabled-methods in System.IO).

There is one important limitation: C# 4.0 dynamic
support is not functional, since it requires dynamic
code generation to work.

Upgraded WCF stack: We still consider this a
preview of the full WCF but has been expanded
significantly.

All new iOS 4.3 APIs have been exposed.

NSDecimal, NSDecimalNumber are now exposed (mostly
for the sake of CorePlot :-)